Tournament
The tournament proper begins with a group stage of 32 teams, divided into eight groups. Seeding
is used whilst making the draw for this stage, whilst teams from the
same nation may not be drawn into groups together. Each team meets the
others in its group home and away in a round-robin format. The winning
team and the runners-up from each group then progress to the next round.
The third-placed team enters the UEFA Europa League.
For this stage, the winning team from one group plays against the
runners-up from another group, and teams from the same association may
not be drawn against each other. From the quarter-finals onwards, the
draw is entirely random, without association protection. The tournament
uses the away goals rule: if the aggregate score of the two games is
tied, then the team who scored more goals at their opponent's stadium
advances.
The group stage is played from September to December, whilst the
knock-out stage starts in February. The knock-out ties are played in a
two-legged format, with the exception of the final. This is typically
held in the final two weeks of May.